MORE than 1000 people have been warned they may been exposed to a rare and fatal brain disease through contaminated surgical instruments used at the Royal Melbourne Hospital since March last year.

The 1056 former patients face years of waiting to discover if they will develop Creutzfeldt-Jakob disease, an incurable illness that can lay dormant for decades.

Concerns arose when it was confirmed a man who underwent brain surgery at the hospital twice last year had died of CJD.

The hospital yesterday sent letters warning all patients who had undergone brain or spinal surgery in the past 18 months that there was an "extremely remote chance" the disease may have been transmitted through instruments used in their operations.

The hospital is destroying all 15,000 neurosurgical instruments and has begun sterilising its entire stock of 300,000 surgical instruments to a higher standard that usual, on the advice of the National CJD Incidents Committee.

Neurology director Stephen Davis said the hospital was taking an "extra conservative" approach by sterilising all instruments, even though they had not been used in operations on the CJD-affected patient.

It is believed to be the first time an Australian hospital has been forced to contact patients after confirming a case of CJD in a former patient.